Police said she abandoned them to have sex with a man in another vehicle.

Jury selection began on Tuesday in at the Mesa County Justice Center.

Jensen’s husband died in a car accident six weeks before his sons died.

Now his parents, Robert and Diane Mathena, are seeking justice.

“It’s been horrible for us, a devastating year and a half that’s for sure,” said Robert. “Don’t want to see her anymore. I want her out of our lives.”

Experiments conducted by the Mesa County Sheriff’s Office show the inside of that SUV could reach temperatures of 145 degrees with the heater on full blast.

“If she’s found guilty of all five charges that would be great,” said Robert.

The Mathenas visit the grave site where their son and grandsons are buried nearly every day.

“We’re thankful we have a grave site to go to. It took us 66 days of fighting her to get the legal right to do the decent thing and bury them. That was our victory in this,” said Robert.

The Mathenas found letters that Heather had written and delivered to the tombstone.

“Never once did she say I’m sorry for killing you or I’m sorry you’re dead. Just all about her and what horrible grandparents we were,” said Robert. “The more time she gets the better off it is for us.”

During jury selection some people said leaving children in a car unattended is inexcusable. But attorneys for the prosecution pointed out that Colorado has no law against it.